SRFI 69 Basic hash tables has been updated and is now available at:

   http://srfi.schemers.org/srfi-69/

According to the author,

This revision incorporates David's comments, removes the guarantee that
hash functions will be called with an appropriate bound parameter,
specifies the value preference of alist->hash-table, changes the rest
parameter list of make-hash-table, and removes type-specific constructor
shorthands and symbol-hash.